The nemas won't survive the winter. Would need to re-apply yearly --

In a home garden, trichogramma, and other beneficials are seldom applied in a timely manner.
In other words, wasted time, effort and $$$.

Thanks Jean!

As Jean states spending money for beneficial insects is largely a waste of your money. However, providing a habitat that will attract them is good gardening. This is one of several articles about growing insectaries that can attract a fairly large number of them.

Here is a link that might be useful: attracting beneficial insects

Thanks Kimmsr, both for the response and the link.

Nematodes have been a great addition to my small garden. They are fairly inexpensive and easy to apply. They will get rid of grubs in your soil and I apply them in the spring and fall. I have used trichogramma for caterpillar control as well as picking the small caterpillars off my plants and smushing them. The best thing I have used, in my garden, in lacewing larvae because they are a general predator that will eat anything with a soft type body. They do great with eating aphids. I don't know why others are saying it's a waste of time and money. If you find a good quality product and reputable company, beneficial insects are a great alternative to pesticides. I've been using them for years and never use any chemicals. I can let you know of some companies I order from, if you you want?

I would James and thank you!